import json
import cv2

ann = json.load(open('annotations.json'))
img = cv2.imread('path/to/image.jpg')
for a in ann['annotations']:
    x, y, w, h = a['bbox']
    cv2.rectangle(img, (int(x), int(y)), (int(x+w), int(y+h)), (0,255,0), 2)
cv2.imshow('check', img)
cv2.waitKey(0)
